Polycrystalline diamond constructions having optimized material composition

Abstract

Diamond bonded constructions include a diamond body comprising intercrystalline bonded diamond and interstitial regions. The body has a working surface and an interface surface, and may be joined to a metallic substrate. The body has a gradient diamond volume content greater about 1.5 percent, wherein the diamond content at the interface surface is less than 94 percent, and increases moving toward the working surface. The body may include a region that is substantially free of a catalyst material otherwise disposed within the body and present in a gradient amount. An additional material may be included within the body and be present in a changing amount. The body may be formed by high-pressure HPHT processing, e.g., from 6,200 MPa to 10,000 MPa, to produce a sintered body having a characteristic diamond volume fraction v. average grain size relationship distinguishable from that of diamond bonded constructions form by conventional-pressure HPHT processing.

What is claimed: 
     
       1. A diamond bonded construction comprising a diamond body comprising a matrix phase of intercrystalline bonded-together diamond crystals and a plurality of interstitial regions dispersed among the bonded-together diamond crystals, the diamond body having a working surface at one location and an interface surface positioned at another location, the body having a diamond volume content with a gradient of greater than about 1.5 percent, the diamond body comprising a catalyst material and a material selected from the group consisting of carbides, nitrides, borides, oxides and combinations thereof disposed within the interstitial regions, and wherein the diamond body has a diamond volume content at the working surface of 98 percent or less according to one of the following criteria:
 the diamond volume fraction is greater than (0.9077)·(the average diamond grain size [^0.0221] 0.0221 ); or 
 the diamond volume fraction is greater than (0.9187)·(the average diamond grain size [^0.0183] 0.0183 ); or 
 the diamond volume fraction is greater than (0.9291)·(the average diamond grain size [^0.0148] 0.0148 ), wherein the average diamond grain size is provided micrometers. 
 
     
     
       2. The diamond bonded construction as recited in  claim 1  wherein the diamond volume content at the interface surface is less than 94 percent by volume and formed from diamond grains sized the same or greater than that at the working surface. 
     
     
       3. The diamond bonded construction as recited in  claim 1  wherein the volume content of the catalyst material changes in a gradient manner within the body moving from the interface surface to the working surface. 
     
     
       4. The diamond bonded construction as recited in  claim 3  wherein the volume content of the catalyst material increases moving from the working surface to the interface surface. 
     
     
       5. The diamond bonded construction as recited in  claim 1  wherein the additional material is a carbide. 
     
     
       6. The diamond bonded construction as recited in  claim 1  wherein the additional material has a volume content that changes moving from the working surface to the interface surface. 
     
     
       7. The diamond bonded construction as recited in  claim 3  wherein the volume content of the catalyst material at the working surface is less than about 6 percent. 
     
     
       8. The diamond bonded construction as recited in  claim 1  further comprising a substrate joined to the diamond body at the interface surface, wherein the substrate is selected from the group of materials consisting of ceramic materials, metallic materials, cermet materials, and combinations thereof. 
     
     
       9. The diamond bonded construction as recited in  claim 1  wherein at least a portion of the diamond body is substantially free of a catalyst material used to form the body at high pressure-high temperature conditions. 
     
     
       10. The diamond bonded construction as recited in  claim 9  wherein a partial region of the diamond body extending a depth from the working surface is substantially free of the catalyst material. 
     
     
       11. A bit for drilling subterranean formations comprising a number of cutting elements operatively attached to a bit body, wherein one or more of the cutting elements comprises the diamond bonded construction recited in  claim 1 . 
     
     
       12. A diamond bonded construction comprising a diamond body comprising a matrix phase of intercrystalline bonded-together diamond crystals and a plurality of interstitial regions dispersed among the bonded-together diamond crystals, the diamond body having a working surface at one location and an interface surface positioned at another location, the body having a diamond volume content with a gradient of greater than about 1.5 percent, the diamond body comprising a catalyst material and a material selected from the group consisting of carbides, nitrides, borides, oxides and combinations thereof disposed within the interstitial regions, and wherein the diamond body has a diamond volume content at the working surface according to one of the following criteria:
 has a sintered average diamond grain size within the range of 2-4 microns, and a has diamond volume fraction greater than 93%; or 
 has a sintered average grain size within the range of 4-6 microns, and has a diamond volume fraction greater than 94%; or 
 has a sintered average grain size within the range of 6-8 microns, and has a diamond volume fraction greater than 95%; or 
 has a sintered average grain size within the range of 8-10 microns, and a has diamond volume fraction greater than 95.5%; or 
 has a sintered average grain size within the range of 10-12 microns, and has a diamond volume fraction greater than 96%. 
 
     
     
       13. The diamond bonded construction as recited in  claim 12  wherein the volume content of the catalyst material changes in a gradient manner within the body moving from the interface surface to the working surface. 
     
     
       14. The diamond bonded construction as recited in  claim 13  wherein the volume content of the catalyst material increases moving from the working surface to the interface surface. 
     
     
       15. The diamond bonded construction as recited in  claim 12  wherein the additional material is a carbide. 
     
     
       16. The diamond bonded construction as recited in  claim 1  wherein the additional material has a volume content that changes moving from the working surface to the interface surface. 
     
     
       17. The diamond bonded construction as recited in  claim 12  wherein the volume content of the catalyst material at the working surface is less than about 6 percent. 
     
     
       18. The diamond bonded construction as recited in  claim 12  further comprising a substrate joined to the diamond body at the interface surface, wherein the substrate is selected from the group of materials consisting of ceramic materials, metallic materials, cermet materials, and combinations thereof. 
     
     
       19. The diamond bonded construction as recited in  claim 12  wherein at least a portion of the diamond body is substantially free of a catalyst material used to form the body at high pressure-high temperature conditions. 
     
     
       20. The diamond bonded construction as recited in  claim 12  wherein a partial region of the diamond body extending a depth from the working surface is substantially free of the catalyst material. 
     
     
       21. A bit for drilling subterranean formations comprising a number of cutting elements operatively attached to a bit body, wherein one or more of the cutting elements comprises the diamond bonded construction recited in  claim 12 . 
     
     
       22. A diamond construction comprising:
 a diamond body comprising a matrix phase of intercrystalline bonded diamond and a plurality of interstitial regions dispersed among the bonded diamond, the diamond body having a working surface at one location and an interface surface positioned at another location, a catalyst material and a carbide material disposed within the interstitial regions, wherein the volume content of both of the catalyst material and the carbide material changes in a gradient manner within the body moving from the interface surface to the working surface, and wherein the volume content of the catalyst material at the working surface is less than about 7 percent; and 
 a substrate joined to the diamond body at the interface surface, wherein the substrate is selected from the group of materials consisting of ceramic materials, metallic materials, cermet materials, and combinations thereof. 
 
     
     
       23. The diamond construction as recited in  claim 22  wherein the volume content of catalyst material increases moving from working surface to the interface surface. 
     
     
       24. The diamond construction material as recited in  claim 22  wherein the volume of the carbide material within the diamond body increases moving from the interface surface to the working surface. 
     
     
       25. The diamond construction as recited in  claim 22  wherein the volume of the carbide material within the diamond body is in the range of from about 1 to 10 percent. 
     
     
       26. The diamond construction as recited in  claim 22  wherein the body has a diamond volume content with a gradient of greater than about 1.5 percent, and wherein the diamond grain size and diamond volume content at the working surface meets one of the following criteria:
 has a sintered average diamond grain size within the range of 2-4 microns, and a has diamond volume fraction greater than 93%; or 
 has a sintered average grain size within the range of 4-6 microns, and has a diamond volume fraction greater than 94%; or 
 has a sintered average grain size within the range of 6-8 microns, and has a diamond volume fraction greater than 95%; or 
 has a sintered average grain size within the range of 8-10 microns, and a has diamond volume fraction greater than 95.5%; or 
 has a sintered average grain size within the range of 10-12 microns, and has a diamond volume fraction greater than 96%. 
 
     
     
       27. The diamond construction as recited in  claim 22  wherein the body has a diamond volume content with a gradient of greater than about 1.5 percent and a diamond volume content of 98 percent or less, and wherein the diamond body has a diamond volume content at the working surface according to one of the following criteria:
 the diamond volume fraction is greater than (0.9077)·(the average diamond grain size [^0.0221] 0.0221 ); or 
 the diamond volume fraction is greater than (0.9187)·(the average diamond grain size [^0.0183] 0.0183 ); or 
 the diamond volume fraction is greater than (0.9291)·(the average diamond grain size [^0.0148] 0.0148 ), wherein the average diamond grain size is provided micrometers. 
 
     
     
       28. The diamond construction as recited in  claim 22  wherein the diamond volume content at the interface surface is less than 94 percent by volume and is formed from diamond grains sized the same or greater than that at the working surface. 
     
     
       29. The diamond construction as recited in  claim 22  wherein the ratio of catalyst material to added carbide is balanced to promote optimum thermal stability within the diamond body. 
     
     
       30. The diamond construction as recited in  claim 22  wherein the ratio of catalyst material to carbide within the diamond body is in the range of from about 6:1 to 1:10. 
     
     
       31. The diamond construction as recited in  claim 22  wherein the ratio of catalyst material to carbide within the diamond body is in the range of from about 3:1 to 1:6. 
     
     
       32. The diamond construction as recited in  claim 22  wherein the ratio of catalyst material to carbide at the working surface is in the range of from about 4:1 to 1:4. 
     
     
       33. A bit for drilling subterranean formations comprising a body and a plurality of cutting elements operatively attached to the body, wherein at least one of the cutting elements comprises the diamond construction as recited in  claim 22 . 
     
     
       34. A bit for drilling subterranean formations comprising:
 a body; and 
 a plurality of cutting elements operatively attached to the body, at least one cutting element comprising a polycrystalline diamond construction comprising:
 a diamond body comprising a matrix phase of bonded together diamond crystals and a plurality of dispersed regions interstitially disposed within the matrix phase, the diamond body having a working surface at one location and an interface surface at another location, wherein a catalyst material and a carbide material is disposed within the interstitial regions and the volume content of the catalyst material decreases in a gradient manner within the body moving from the interface surface to the working surface, and wherein the volume content of the catalyst material at the working surface is less than about 6 percent; and 
 
 a substrate joined to the diamond body at the interface surface, wherein the substrate is selected from the group of materials consisting of ceramic materials, metallic materials, cermet materials, and combinations thereof. 
 
     
     
       35. The bit as recited in  claim 34  wherein the volume content of diamond changes within the body by greater than 1.5 percent. 
     
     
       36. The bit as recited in  claim 34  wherein the volume content diamond changes within the body from 2 to 6 percent. 
     
     
       37. The bit as recited in  claim 34  wherein the body has a diamond volume content with a gradient of greater than about 1.5 percent and a diamond volume content of 98 percent or less, and wherein the diamond body has a diamond volume content at the working surface according to one of the following criteria:
 the diamond volume fraction is greater than (0.9077)·(the average diamond grain size [^0.0221] 0.0221 ); or 
 the diamond volume fraction is greater than (0.9187)·(the average diamond grain size [^0.0183] 0.0183 ); or 
 the diamond volume fraction is greater than (0.9291)·(the average diamond grain size [^0.0148] 0.0148 ), wherein the average diamond grain size is provided micrometers. 
 
     
     
       38. The bit as recited in  claim 34  wherein the diamond grain size and diamond volume content at the working surface meets one of the following criteria:
 has a sintered average diamond grain size within the range of 2-4 microns, and a has diamond volume fraction greater than 93%; or 
 has a sintered average grain size within the range of 4-6 microns, and has a diamond volume fraction greater than 94%; or 
 has a sintered average grain size within the range of 6-8 microns, and has a diamond volume fraction greater than 95%; or 
 has a sintered average grain size within the range of 8-10 microns, and a has diamond volume fraction greater than 95.5%; or 
 has a sintered average grain size within the range of 10-12 microns, and has a diamond volume fraction greater than 96%. 
 
     
     
       39. The bit as recited in  claim 34  wherein a region of the body adjacent the working surface is substantially free of the catalyst material. 
     
     
       40. The bit as recited in  claim 34  comprising a number of blades projecting outwardly from the body, and wherein the cutting elements are attached to the blades. 
     
     
       41. The bit as recited in  claim 34  comprising a number of legs extending outwardly from the body and cones rotatably disposed on the legs, wherein the cutting elements are attached to the cones.